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Finding the Fourth Proportional to 648.45, 972.36 and 215.55

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Solution

The fourth proportional to 648.45, 972.36 and 215.55 is: 323.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.45 : 972.36 = 215.55 : x
  2. Step 2: Convert to fraction form
    648.45/972.36 = 215.55/x
  3. Step 3: Cross multiply
    648.45x = 972.36 × 215.55
  4. Step 4: Simplify right side
    648.45x = 209,592.20
  5. Step 5: Solve for x
    x = 209,592.20/648.45
  6. Step 6: Final answer
    x = 323.22

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.